The opinion that the ability of children with autism to form emotional relationships is impaired is generally known. The aim of the present study was to compare the behavior of 4–6 year old children with autism, children with Down syndrome and normally developing children in a modified Strange Situation. Thirty-one types of behavior were recorded and assigned to four categories: initiative towards the mother, initiative towards the stranger, exploration, avoiding contact. In all groups the contact with the mother was most intense at the beginning of the test; there were more attempts at initiating contact with the stranger when the mother was present in the room; the separation anxiety and seeking contact with the mother upon reunion were also observed. The differences between the children with autism and other children of the same age were small and directly related to the deficits typical for autism (mainly related to the joint-attention disorder).